Classes

Variables

Variable Documentation

BaseFab emulates the Fortran array concept. Useful operations can be performed upon BaseFab's in C++, and they provide a convenient interface to Fortran when it is necessary to retreat into that language.

`BaseFab' is a template class. Through use of the template, a `BaseFab' may be based upon any class. So far at least, most applications have been based upon simple types like `integer's, `real's, or `doubleprecision's. Most applications do not use BaseFab's directly, but utilize specialized classes derived from BaseFab.

It will be easier to use a `BaseFab' if you understand the following concepts. `BaseFab' objects depend on the dimensionality of space (indirectly through the DOMAIN `Box' member). It is typical to define the macro `CH_SPACEDIM' to be 1, 2, or 3 to indicate the dimension of space. See the discussion of class `Box' for more information. A `BaseFab' contains a `Box' DOMAIN, which indicates the integer indexing space over which the array is defined. A `BaseFab' also has NVAR components. By components, we mean that for each point in the rectangular indexing space, there are NVAR values associated with that point. A Fortran array corresponding to a `BaseFab' would have (CH_SPACEDIM+1) dimensions.

By design, the array layout in a `BaseFab' mirrors that of a Fortran array. The first index (x direction for example) varies most rapidly, the next index (y direction), if any, varies next fastest. The component index varies last, after all the spatial indices.

It is sometimes convenient to be able to treat a sub-array within an existing `BaseFab' as a `BaseFab' in its own right. This is often referred to as 'aliasing' the `BaseFab'. Note that when aliasing is used, the BaseFab's domain will not, in general, be the same as the parent BaseFab's domain, nor will the number of components. BaseFab is a dimension dependent class, so CH_SPACEDIM must be defined as either 1, 2, or 3 when compiling.